1. Field
The present disclosure relates generally to an electronic device, a method of controlling the electronic device, and a computer-readable recording medium having stored thereon computer program code for executing the method of controlling the electronic device.
2. Description of Related Art
Electronic devices generate an imaging signal by exposing an imaging device to light during an exposure time. The imaging device may be exposed to light only during the exposure time via a shutter. The shutter used in the electronic devices may include a global shutter method and a rolling shutter method.
The global shutter method is a method, according to which the whole screen is reset at the same time and is started to be exposed to light. The global shutter method does not generate flickers, but requires an additional storage space in a sensor, thereby having low efficiency and causing increased expenses.
The rolling shutter method is a method, according to which light exposure is controlled in a line unit. The rolling shutter method does not require an additional storage space in a sensor. However, the rolling shutter method generates the jello effect, which is related to an occurrence of an up and down disparity of a screen.
Meanwhile, when electronic devices photograph a subject under illumination using an alternating current (AC) power source, a variation in brightness of the illumination occurs over time. Here, a frequency of the brightness of the illumination is proportionate to a frequency of the AC power source. For example, a frequency of an AC power source in Korea is a 1/60 second, and when a subject is photographed under illumination using this AC power source, a variation in brightness of the illumination occurs to generate a frequency of the brightness that is proportionate to the 1/60 second. In the case of a global shutter that exposes the whole screen to light, the variation in the brightness of the illumination is uniformly reflected on the whole screen. Accordingly, when the global shutter is used, a flicker phenomenon does not occur on the screen. On the contrary, when a rolling shutter is used, the variation in the brightness of the illumination is not uniformly reflected on the screen. For example, due to the variation in the brightness of the illumination, a captured image may have a stripe shape. This phenomenon, in which the brightness of a screen is not uniform based on the variation of the brightness of the illumination, is referred to as a flicker.
When the flicker phenomenon occurs, brightness varies depending on a region of a captured image, and thus, image quality of the captured image may be reduced.